The present invention relates to a needle set which can be profitably used for double-blind test for strictly evaluating the therapeutic effect of acupuncture in which it is masked from both of the subject and the practitioner whether a true needle or a placebo needle is used, how deep the needle is inserted, what is the diameter of the needle, and where the needle is inserted (acupoint or non-acupoint). This invention further relates to a safety needle and placebo needle suitably used as a member of the double-blind needle set. This invention further relates to a safety needle which does not cause any infection in the patient, the practitioner, and the disposer for used needles.
It is said that the most excellent and practical method among the methods for evaluating the therapeutic effect of acupuncture is a single-blind method in which only the subject is blinded. In the experiment based on the single-blind method, the control group receives placebo stimulation resembling a needle insertion on an acupoint while the experimental group receives stimulation with true needle insertion at the same acupoint; the results from the two groups are compared; and the therapeutic effect is evaluated.
The currently proposed methods for giving placebo stimulation includes the following three:
(1) To place a guide tube instead of a needle on a site of the skin, and tap the top end of the guide tube;
(2) To transform the tip of a needle into impenetrable to the skin, place the transformed tip on a site of the skin, and press the upper end of the needle (see, for example, The Lancet, vol. 352, Aug. 1998, pp. 364-365); and
(3) To place an electrode for percutaneous electrical stimulation on a site of the skin.
Methods (1), (2) and (3) are all employed in experiments based on the single-blind method. With methods (1) and (2), it is possible to completely make the subject unaware of whether the stimulation applied is by a true needle inserted or by a placebo needle pressed, as long as the experiment is properly conducted. This was indeed confirmed for method (2) (see, for example, The Lancet, vol. 352, Aug. 1, 1998, pp. 364-365). However, with method (3), it is hardly possible to mask the nature of stimulation from the subject, because the shape of device used for stimulation, sensation the subject felt induced by a stimulation, etc. are clearly different from those of true needle insertion.
However, with all the above methods aimed at giving placebo stimulation, it is impossible to make the practitioner unaware of the nature of stimulation, that is, the methods can not mask the practitioner whether he applied a true needle or a placebo needle. Namely, all the above methods are inadequate to serve as a placebo stimulation to be given to a control group. When the practitioner applies a needle to a subject, the practitioner feels, through his fingers and hands, the needle making a puncture on the skin, penetrating the skin, and advancing deep into the human body, or he is aware of the point at needling before needle application. Thus, it has been thought impossible to mask the nature of stimulation from the practitioner. Under such current situations, the Consensus Development Conference of US National Health Institute (NIH) concludes that, for the evaluation of acupuncture, it can not help adopting single-blind test because in acupuncture study it is possible to mask the nature of stimulation only from the subject (The Lancet, vol. 352, Sep. 19, 1998, p. 992).
However, because, with single-blind test, expectation or zeal of the practitioner during therapy is transmitted to the subject, a demand is manifest for double-blind method which can mask the nature of stimulation from the practitioner as well as from the subject, to scrutinize the effect of acupuncture.
The acupuncture therapy currently widely in use is based on the insertion technique using the guide tube. The therapy based on the insertion technique is executed with a needle and the guide tube separately prepared. The practitioner inserts the needle into a guide tube by one hand, and forms Oshide(the hand by which to hold the guide tube or the needle during the needle insertion or the needle removal) by placing the thumb and the index finger of the other hand being lightly in contact with each other on a site of the skin; and inserts the guide tube contained the needle between the pads of the thumb and the index finger of Oshide and holds the guide tube adjusting a needle insertion angle being preferable; and taps the top end of the needle handle with the pad of the index finger of Sashide(or the hand by which to insert or remove the needle) to open thereby a puncture on the skin(usually, the guide tube used for the insertion therapy has the length shorter by about 3-4 mm than the total length of the needle, and thus the needle is inserted by that difference into the human body by tapping with the pad of the index finger). After the puncture is opened, the guide tube alone is removed to leave the partly sticking needle on the site; the Oshide directly holds the needle body, and inserts it into the human body with the holding needle. When the needle reaches to a desired depth, the Oshide keeps holding the needle body, or leaves the needle to stand there for an arbitrary period (in-situ needle). Then, the Oshide is formed around the needle to extract it from the body. Immediately after removal, the used needle including its needle body and its tip is bare.
As seen above, during the insertion therapy with a guide tube, the guide tube and the needle body are separated. Thus, the Oshide directly contacts with the needle body when the practitioner inserts or removes the needle into or from the body. Accordingly, before insertion, the needle body may be contaminated through contact with the fingers and hands of the practitioner. Because, for removal, the needle uncovered with the guide tube is extracted from the patient""s body, the practitioner""s fingers and hands may be contaminated with the patient""s body fluid through contact with the bare needle body and tip of the needle. The same risk persists even when the practitioner wears gloves during therapy.
The practitioner or the disposer who handles acupuncture needles may damage himself by accidental contact with a used needle with its bare needle body and its tip. Currently, at acupuncturist training schools and clinical centers used needles are disposed into a cylindrical trash case having a bottom diameter of 8 cm and a height of 17 cm. If the case becomes full, used needles are removed by hand and put into a cardboard box for medical waste. During disposal, when the practitioner put away used needles into a trash case, or when disposer transfers used needles from the trash case to a cardboard box, he may damage himself by accident. Indeed, there was reported such a case.
To prevent contamination in acupuncture therapy, a method is proposed in which the practitioner wears finger covers or operation gloves during therapy. However, this method poses a number of problems: wearing covers or gloves is a nuisance to the practitioner, and the practitioner""s fingers and hands may contact with the contaminated surfaces of covers and gloves.
A variety of means to prevent infection during therapy, or during disposal of used needles have been proposed.
Recently, covering the needle body with a coat (Japanese Patent Laid-Open No. Sho 57-131446) and covering the lowest end of a needle with a tube sufficiently small to enter through the inner space of a guide tube (Japanese Patent Laid-Open No. Sho 57-177752) are proposed. With these methods, a needle body and a guide tube are separated from each other during therapy, and they are separately disposed of after therapy. Namely, when disposed of, both the needle body and its tip are bare, and thus these methods do not take into account the risk of a third person who may be exposed, after therapy, to contamination by touching such a needle body or a guide tube accidentally.
The first object of this invention is to provide a safety needle and a placebo needle ensuring the introduction of a double-blind method whereby it is possible to make both the practitioner and the subject unaware of whether the needle applied is a true needle or a placebo needle, or whether the insertion point corresponds with an acupoint or not, thereby enabling a strict evaluation of the effect of acupuncture therapy.
Another object of this invention is to provide a safety needle free from the risk of infection, with which infection from the patient to the practitioner, and from the practitioner to a third person, and to provide a safety needle free from the risk of exposure to infection of the disposer who might otherwise contaminate himself by damaging himself by accident with the needle when disposing.
A further object of this invention is to provide a needle set for double-blind test with which it is possible to mask the depth of needle insertion, and the diameter of needle body.
The safety needle of the present invention to achieve the above object, particularly the safety needle of the present invention to be incorporated into a needle set for double-blind test comprises: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) the needle body movably held by the stuffing which has the length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further at the moment when the needle point reach a specified insertion depth; (5) wherein the guide tube is longer than the insertion depth of the needle body.
The placebo needle of the present invention to achieve the above object, or the placebo needle of the present invention to be incorporated into a needle set for double-blind test comprises: (1) a guide tube; (2) one or more first stuffings which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) one or more second stuffings which are plugged into lower position of the guide tube and fixed, to give similar sensation to the skin puncture and the tissue penetration during passage of the needle body therethrough to reach a specified depth; (4) the needle body movably held by the first stuffing which has the length sufficiently long to allow its point to stop just on/above the skin surface when the needle body is advanced through the cavity of the guide tube as far as possible; and (5) a stopper which is mounted to the lower end of the handle needle attached to the top of the needle body, or which is mounted to the upper end of the guide tube, and prevents the needle handle from advancing further into the guide tube when the point of the needle body reaches just on/above the skin surface.
Another placebo needle of the present invention comprises: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to the needle body during its passage therethrough; (3) the needle body movably held by the stuffing holding needle body which has the length sufficiently long to allow its point to stop just on/above the skin surface when the needle body being advanced through the cavity of the guide tube as far as possible; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further into the guide tube when the point of the needle body being advanced through the cavity of the guide tube reaches just on/above the skin.
It is possible to combine the safety needle and the placebo needle into a needle set suitably used for double-blind test.
The needle set of this invention for double-blind test incorporating a placebo needle with the second stuffing, is characterized by that, for the safety needle and placebo needle, the guide tubes are the same in length, the portions of the needles bodies protruding from the top end of the guide tubes are the same in length, the needle handles are the same in length, and the distance from the lowest end of the needle body of the safety needle to the skin surface is the same as the distance from the lowest end of the needle body of the placebo needle to the upper surface of the second stuffing; the upper surface of the second stuffing is placed at a level higher than the bottom end of the guide tube by an amount equal to the insertion depth of the safety needle; and the two needles can not be distinguished from their appearances. It is necessary for blinding both the practitioner and the subject regarding whether a real needle or a placebo needle applied to make the safety needle and the placebo needle look so similar that they can not be distinguished from their appearances. For this purpose, the guide tube should be preferably opaque.
The needle set of this invention for double-blind test incorporating a placebo needle with no second stuffing is characterized by that: for the safety needle and placebo needle, the guide tubes are the same in length, the portions of the needles bodies protruding from the top end of the guide tube are the same in length, and the needle handles are the same in length; and the two needles can not be distinguished from their appearances. It is necessary for blinding both the practitioner and the subject regarding whether a real needle or a placebo needle applied to make the safety needle and the placebo needle look so similar that they can not be distinguished from their appearances. The stuffing for placebo needle having a property as described above is preferably made of a material which has resistance to cancel resistance the practitioner would feel when he inserts a needle into the skin, and advances it through the skin. The needle set incorporating such a placebo needle for double-blind test may be suitable for an acupuncturist unaccustomed with the technique as well as for a practitioner without acupuncture license, or may be suitable for in a case where shallow insertion of a safety needle is needed, the patient has a thin and soft skin, or the site applied has a soft subcutaneous tissue.
Another needle set of this invention for double-blind test comprises: (1) a group of safety needles selected according to the specified double-blind test from needles which are different in at least one of the following properties, the material, length, color and shape of the needle handle; the material, total length, the diameter of the needle body; length of the protruding portion of the needle body from the upper end of the guide tube; the distance from the lowest end of the needle body to the skin surface; the insertion depth of the needle body; the material, length, color and shape of the guide tube; and the material, quantity, the number and position of the stuffing, (2) a group of placebo needles selected from needles which are different in at least one of the following properties, the material, length, color and shape of the needle handle; the material, total length, the diameter, length of the protruding portion of the needle body from the upper end of the guide tube; distance from the lowest end of the needle body to the upper surface of the second stuffing; the material, length, color and shape of the guide tube; and the material, quantity, the number and the position of the first stuffing; and the material, the quantity, the number and the position of the second stuffing; and (3) a set for double-blind test consisting of the safety needle group and the placebo needle group.
With the needle set for double-blind test, it is possible to choose arbitrarily appropriate combination for the modality or an appropriate numerical combination of safety and placebo needles from the viewpoint of the above each character according to the specified double-blind test.
The length of the guide tube is defined as the length of the guide tube including the thickness of stopper if the guide tube has a stopper protruding from its top end.
The length of a needle body should be determined by measuring from the lowest end of a stopper to the point, if the needle handle has the stopper at its lowest end, and that stopper protrudes from the lowest end of the needle handle, or if the stopper is placed along the needle body at an arbitrary position lower than the lowest end of the needle handle.
The guide tube of a safety needle or a placebo needle may have an adhesive or sucking pedestal on its bottom end to keep both kind of needle stable on the skin surface, thereby ensuring the fixation of the guide tube on the skin surface.